A Symptom Diagnosis

IMPORTANT: The following steps must be completed before using the symptom tables.

1. Perform Diagnostic System Check - Instrument Cluster or Diagnostic System Check - Driver Information Systems or Diagnostic System Check - Audible Warnings before using the Symptom Tables in order to verify that all of the following are true:
- There are no DTCs set.
- The control module(s) can communicate via the serial data link. Diagnostic System Check - Instrument Panel Cluster Diagnostic System Check - Driver Information Systems Diagnostic System Check - Audible Warnings
2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following:
- Instrument Panel Cluster (IPC) Description and Operation.
- Indicator/Warning Message Description and Operation.
- Driver Information Center (DIC) Description and Operation
- Audible Warnings Description and Operation.

Visual/Physical Inspection
- Inspect for aftermarket devices which could affect the operation of the Instrument Cluster or Audible Warning Systems. Refer to Checking Aftermarket Accessories in Diagnostic Aids.
- Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
- Inspect for proper fluid levels.

Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

Gages and Odometer
- Engine Coolant Temperature Gage Inaccurate or Inoperative
- Engine Oil Pressure Gage Inaccurate or Inoperative
- Fuel Gage Inaccurate or Inoperative (Dual Tanks) or Fuel Gage Inaccurate or Inoperative (Single Tank)
- Hourmeter Inaccurate or Inoperative
- Instrument Cluster Inoperative
- Odometer Trip/Reset Switch Inoperative
- Speedometer and/or Odometer inaccurate or Inoperative (Gas) or Speedometer and/or Odometer Inaccurate or Inoperative (Diesel 6.6L)
- Tachometer Inaccurate or Inoperative (Gas) or Tachometer Inaccurate or Inoperative (Diesel 6.6L)
- Transmission Fluid Temperature Gage Inaccurate or Inoperative
- Volt Gage Inaccurate or Inoperative

Indicators
- 4WD Indicator Always On in Transfer Case-NVG 261-NP2 4WD Indicator Always On
- 4WD Indicator Inoperative in Transfer Case-NVG 261-NP2 4WD Indicator Inoperative
- ABS Indicator Always On in Antilock Brake System ABS Indicator Always On
- ABS Indicator Inoperative in Antilock Brake System ABS Indicator Inoperative
- Air Bag Indicator Circuit Malfunction in Restraint Systems Symptom Related Diagnostic Procedures
- Brake Warning Indicator Always On in Hydraulic Brakes Brake Warning Indicator Always On
- Brake Warning Indicator Inoperative in Hydraulic Brakes Symptom Related Diagnostic Procedures
- Cruise Control Indicator Always On in Cruise Control Testing and Inspection
- Cruise Control Indicator Inoperative in Cruise Control Testing and Inspection
- Fasten Safety Belt Indicator/Chime Always On Seat Belts Fasten Safety Belt Indicator/Chime Always On
- Fasten Safety Belt Indicator/Chime Inoperative in Seat Belts Fasten Safety Belt Indicator/Chime Inoperative
- Fog Lamp Indicator Inoperative in Lighting Systems Testing and Inspection
- High Beam Indicator Always On in Lighting Systems Testing and Inspection
- High Beam Indicator Inoperative in Lighting Systems Testing and Inspection
- Low Traction Indicator Always On in Antilock Brake System Low Traction Indicator Always On
- Low Traction Indicator Inoperative in Antilock Brake Low Traction Indicator Inoperative
- Malfunction Indicator Lamp (MIL) Always On in Computers and Controls Systems 4.3L Symptom Related Diagnostic Procedures
- Malfunction Indicator Lamp (MIL) Inoperative in Computers and Controls Systems - 4.3L Symptom Related Diagnostic Procedures
- Malfunction Indicator Lamp (MIL) Always On in Computers and Controls Systems - 4.8L, 5.3L, and 6.0L Symptom Related Diagnostic Procedures
- Malfunction Indicator Lamp (MIL) Inoperative in Computers and Controls Systems -- 4.8L, 5.3L, and 6.0L Symptom Related Diagnostic Procedures
- Malfunction Indicator Lamp (MIL) Always On in Computers and Controls Systems - 6.6L Symptom Related Diagnostic Procedures
- Malfunction Indicator Lamp (MIL) Inoperative in Computers and Controls Systems - 6.6L Symptom Related Diagnostic Procedures
- PRNDL Display Park Indicator Inoperative
- Tow/Haul Switch/Indicator Always On or Inoperative in Automatic Transmission - 4L60E Testing and Inspection
- Tow/Haul Switch/Indicator Always On or Inoperative in Automatic Transmission - 4L80E Testing and Inspection
- Traction Off Indicator Always On in Antilock Brake System Traction Off Indicator Always On
- Traction Off Indicator Inoperative in Antilock Brake System Symptom Related Diagnostic Procedures
- Turn Signal Lamps and/or Indicators Always On or Flashing in Lighting Systems Testing and Inspection
- Turn Signal Lamps and/or Indicators Inoperative in Lighting Systems Testing and Inspection

Message Center
- Cargo Lamp On Indicator Always On in Lighting Systems Testing and Inspection
- Cargo Lamp On Indicator Inoperative in Lighting Systems Testing and Inspection
- Change Engine Oil Indicator Always On
- Change Engine Oil Indicator Inoperative
- Charge Indicator Always On in Engine Electrical Charge Indicator Always On
- Charge Indicator Inoperative in Engine Electrical Charge Indicator Inoperative
- Engine Oil Pressure Indicator Always On
- Engine Overheated Indicator Always On in Cooling System Engine Overheated Indicator Always On
- Engine Coolant Temperature Indicator Always On in Cooling System Engine Coolant Temperature Indicator Always On
- Low Engine Coolant Indicator Always On in Cooling System Low Engine Coolant Indicator Always On
- Low Engine Oil Level Indicator Always On
- Low Engine Oil Level Indicator Inoperative
- Low Washer Fluid Indicator Malfunction in Wipers/Washer Systems Testing and Inspection
- Selectable Ride Indicator Always On in Selectable Ride Selectable Ride Indicator Always On
- Selectable Ride Indicator Inoperative in Selectable Ride Selectable Ride Indicator Inoperative
- Service 4W Steer Indicator Always On in Rear Wheel Steering Service 4W Steer Indicator Always On
- Service 4W Steer Indicator Inoperative in Rear Wheel Steering Service 4W Steer Indicator Inoperative
- Service Indicator Always On in Transfer Case NVG 236/246 NP8 Symptom Related Diagnostic Procedures
- Service Indicator Inoperative in Transfer Case NVG 236/246 NP8 Symptom Related Diagnostic Procedures
- Service Indicator Always On in Transfer Case NVG 263-NP1 Symptom Related Diagnostic Procedures
- Service Indicator Inoperative in Transfer Case NVG 263-NP1 Symptom Related Diagnostic Procedures
- Water-in-Fuel Lamp Always On in Computers and Controls Systems - 6.6L.
- Water-in-Fuel Lamp Inoperative in Computers and Controls Systems - 6.6L

Instrument Cluster Dimming
- Interior Backlighting Inoperative in Lighting Systems Testing and Inspection
- Interior Backlighting Does Not Dim in Lighting Systems Testing and Inspection

Driver Information Center (DIC)
- Driver Information Center (DIC) Inoperative
- Driver Information Center (DIC) Switch(es) Inoperative

Audible Warnings
- Chime Always On
- Chime Inoperative

Console
- Hot and Cold Cupholder Inoperative
- Thermoelectric Cooler Inoperative

For a description of the RPO Code(s) shown in this article or any of the images therein, refer to the RPO Code List found at Vehicle/Application RPO Codes